The present invention relates to an explosion preventive rotation crusher which crushes into small pieces big-size disused articles such as furniture and the like and non-combustible garbage such as empty cans and bottles and the like.
With development of industries and economies, people have changed their ways of life and refuse from homes and factories has become various in kind and increased in quantity. In big cities home garbage such as left-over foods, waste paper and the like and big-size disused articles (such as furniture) and non-combustible garbage are collected separately. The home garbage is burned in an incinerator. On the other hand, the big-size disused articles and the non-combustible garbage are crushed into small pieces by horizontal axis type or vertical axis type rotation crushers and then are grouped into combustible refuse, metal, glass, and others. The combustible refuse is burned and metal is put to reuse.
Both the horizontal axis type and the vertical axis type rotation crushers which crush big-size disused articles and non-combustible refuse, are so structured that hammers rotate at high speed inside the crushers to strike, sear and grind the big-size articles and non-combustible refuse.
Consequently, in the event that combustible refuse happens to have been mixed in the refuse to be crushed, such as big-size articles and incombustible refuse, a danger of explosions and fires occurs. In fact, explosions frequently occur at refuse treating facilities which dispose of such big-size articles in disused and incombustible refuse.
A known explosion preventive rotation crusher treating big-size disused articles and incombustible refuse is filled with steam, nitrogen gas, CO.sub.2 and the like to keep pressure inside the crusher within a predetermined range, thereby making oxygen content almost nil inside the crusher to prevent explosions. Since the crusher is kept pressurized and filled with steam or the like, explosions are prevented even if combustible refuse is mixed in the refuse to be crushed.
But, the above stated rotation crusher still has many disadvantages and problems to be dealt with. For instance, it is very uneconomical that so much steam or the like must be fed into the crusher to keep the crusher at a certain pressurized state. Consequently, in order to solve the problem, it is very important to know exactly the critical oxygen content which can prevent explosions (the explosion preventive critical oxygen content) and further it is also imperative to measure speedily, exactly and easily the distribution of oxygen in the crusher.